Prior to me buying an ASUS 660 Direct CU II a couple of months back, for the home machine, I had a similar dilemma. The deciding factor for you might be a different metric, however, for me it was the acoustics and then performance and power consumption. Plus I wanted to stay within an approximate $200 CAD price limit.

I have a MSI twin Frozr III 7870 and love it. I would personally recomend a MSI/Sapphire 7870 as they are generally the better overclockers and definately have the better coolers then the asus cards at this point. When I got mine I researched ALOT on the various 7870 available at the time from all makers I could get here in canada, generally speaking, the sapphire one is a slightly better designed cooler but its easier to RMA an msi gpu here in canada then a sapphire, so I got the msi one. Main reason being while the Asus DC II cooler on the 7870 was ok, overclocking performance was average, once loaded the DC II cooler would get quite loud underload compared to the others, this was partly to do with one of the fans having X blades and the other having X blades more. Current cards "should" have the same amount of blades and be "tuned" a bit, but the other coolers that are dual bladed are just better coolers this generation, especially the sapphire/msi coolers.